Referring to FIGS. 5(a), 5(b), 6(a), 6(b) and 7, the following description discusses a conventional cordless telephone set having a charger which is used as either a desktop charger or a wall charger and is capable of charging a secondary battery included in a handset when the handset is set in the charger which is put on a desk or wall.
Provided on the front face of a handset 30 of the cordless telephone set including therein a secondary battery are a transmitter section (microphone) 31, a receiver section (speaker) 32, an operating section 33, and an indentation section 34 below the receiver section 32. Attached to the bottom face of the handset 30 is a pair of charging terminals 35.
A charger 40 charges the secondary battery included in the handset 30. A portion of the charger 40 on which the receiver section 32 of the handset is positioned is recessed. A holder section 41 of the charger 40 is formed into the same shape as the rear face of the handset 30. The bottom side of the holder section 41 is provided with conducting terminals 43 with which the charging terminals 35 of the handset 30 are brought into contact. There is a separate protruding piece 42 which is freely attachable to and detachable from a portion of the charger 40 corresponding to the indentation section 34 of the handset 30.
The following description explains the cordless telephone set having the above-mentioned structure, in particular, how the secondary battery in the handset 30 is charged when the charger 40 is used as a desktop charger. In this case, as illustrated in FIG. 6(a), when the handset 30 is placed on the charger 40 with its front face down, the receiver section 32 of the handset 30 is positioned to fit into the recessed portion of the holder section 41. When the receiver section 32 fits into the recessed portion, the charging terminals 35 of the handset 30 are in contact with the conducting terminals 43 of the charger 40, thereby charging the secondary battery in the handset 30.
On the other hand, when the handset 30 is placed on the charger 40 with its front face up, as illustrated in FIG. 6(b), the rear face of the handset 30 is placed over the portion of the holder section 41 having the same shape as the rear face of the handset 30. At this time, the charging terminals 35 of the handset 30 are brought into contact with the conducting terminals 43 of the charger 40, and the secondary battery in the handset 30 is charged.
Next, how the secondary battery in the handset 30 is charged when the charger 40 is used as a wall charger is explained. As illustrated in FIG. 7, the separate protruding piece 42 is attached to the holder section 41 to stick out toward the recessed portion thereof, and the indentation section 34 of the handset 30 is positioned to engage with the separate protruding piece 42 so as to prevent the handset 30 from dropping from the charger 40. At this time, the charging terminals 35 of the handset 30 come into contact with the conducting terminals 43 of the charger 40, thereby charging the secondary battery in the handset 30.
However, with a conventional apparatus, when the charger is used as a wall charger, it is necessary to provide a separate member in order to prevent the handset from dropping from the charger. Moreover, it is necessary to change the position of the separate member depending on the state of the charger, i.e., whether it is installed on a desk or wall.
As described above, when the charger is used as a desktop charger, the secondary battery is charged by setting the handset on the charger either with its front face down or up. Namely, if the charger is placed on a desk, it is possible to reversibly set the handset on the charger. However, if the charger is mounted on a wall, in order to charge the secondary battery, it is necessary to set the handset on the charger with its front face facing the wall. In other words, the secondary battery can not be charged if the front face of the handset faces outside when the charger is mounted on the wall.